1) Field of the Invention
The present invention relates to a method of and a system for recycling toner easily and effectively.
2) Description of the Related Art
There has been an increasing awareness about the importance of environmental problems in today's world than it was before. Now a day, companies are assessed based on their contribution to environmental protection. Therefore, it has become vital for companies to carry out activities that lead to environmental protection. These activities include establishing recycling systems by which products, parts and materials can be recycled and reused in order to reduce waste and to make effective use of resources.
The recycling processes can be broadly divided into following six types:
1. Reuse by the User
A user of a product carries out the recycling by reusing the entire or a part of the product. If we consider an example of a copier, when a user himself refills a toner receptacle (toner bottle) and reuses the toner receptacle. In such case, there is no decrease in the value of object, the toner bottle, to be recycled. The advantages of this recycling process are that the burden on the environment is reduced to maximum extent and moreover, the processing cost is minimum.
2. Reuse of the Entire Product
A product already used is recovered from market (hereinafter, “recovered machine”). A prescribed recycling treatment is carried out on this recovered product to reuse as a recycled machine. This recycling process allows the major part of the product to be reused as it was used before. The advantage of this recycling method is that the burden on the environment is reduced to a great extent.
3. Reuse of the Parts
The parts and units removed from the recovered machine are reused as new parts and units. Since the parts and units that can be recycled need not be manufactured again, the advantage of this recycling method is that the burden on the environment is reduced to a large extent.
4. Recycling of Materials
Recycling of materials is a recycling process in which a recovered machine is disassembled in units of materials and the raw material obtained is classified, processed, and reused. This recycling process involves recycling of a closed loop material and an open loop material. The closed loop material is a material which can be reused in only the same field as the original product. On the other hand, the open loop material is a material which can be reused even in a different field.
5. Retransformation into Raw Material
In this recycling process, recovered machine is disassembled, classified and then transformed into a raw material for reuse. The retransformation into raw material can realize zero waste.
6. Energy Recovery
Energy recovery is a recycling process of using an energy generated by processing the recovered objects. An example of energy recovery is burning of recovered plastic and using the generated heat energy.
The six recycling processes are mentioned in a desirable order. In other words, the most desirable recycling process in general is the reuse by the user. The recycling process desirable next is the reuse of the entire product and still next is the reuse of the parts. It is important for companies to continue recycling by means mentioned in the order above while considering the economic aspect in order to promote the recycling.
However, products go on becoming outdated (old) in the market. A time comes for a product when it is no more useful to the market (user) and recycling of a product is not worth economically. Therefore, in reality, it is impossible to recycle a recovered machine semi permanently just by the reuse by the user. In other words, the user cannot recycle an outdated product. Furthermore, depending on the degree of outdating of the product, a desired order of the recycling processes may be different, or even may be reverse from the order mentioned above. For this reason, the companies have to carry out a plurality of recycling processes instead of carrying out only specified ones.
Further, a recycling process differs depending on the product itself. Again, for a recovered machine of one type, a recycling process differs depending on parts and units in a recovered machine. Therefore, it is necessary to carry out a plurality of recycling processes almost at the same time in order to promote recycling.
Japanese Patent Application Laid Open Publication No. 2000-181958 teaches a recycling system that can carry of the recycling processes efficiently. FIG. 15 illustrates the recycling system published in the Japanese Patent Application Laid Open Publication No. 2000-181958. This recycling system has a plurality of stages indicated by reference numerals from (1) to (20). Stage (1) is a manufacturing stage of a raw material. A raw material supplier, in general, manufactures the raw material. Stage (2) is a stage of material manufacturing using a new raw material or a recycled raw material. In general, a material manufacturer manufactures and supplies raw materials.
Stage (3) is a stage of manufacturing parts using new parts or recycled parts. In general, a parts manufacturer manufactures and supplies parts. Stage (4) is a stage of assembling products using new parts or recycled parts. In general, a product manufacturer assembles and supplies products. Stage (4) is a stage of selling of a product in which new parts or recycled parts are used. In general, dealer sells products.
Stage (6) is a stage of use and maintenance of product. In general, user (market) uses a product. Stage (7) is a stage of reuse by user. Stage (8) is a stage of product recovery and selection. In general, products are recovered from users (market) and brought to a prescribed recovery center where the products are sorted for the next stage.
Stage (9) is a stage of recycling of a product. In general, the recovery center sends,recovered products to a prescribed recycling center for recycling. Stage (10) is a stage of carrying out dismantling and classification of products. In general, the recovery center sends products to a prescribed recycling center for recycling. Stage (11) is a stage of recycling of parts. In general, the recycling center sends products to a prescribed parts recycling center for recycling of parts. Stage (12) is a stage of supplying the recycled parts to a manufacturer of products of other field. Stage (12) corresponds to the open recycling.
Stage (13) is a stage of breaking of parts (or products) into pieces. Parts made of a single material and parts made of a plurality of materials are crushed and classified in this stage. In general, recycling center (in some cases recovery center) sends parts (products) to prescribed shredding contractor for breaking and classification. Stage (14) is a stage of recycling of materials. Crushed material that can be recycled is sent from the previous stage (13) to a material recycling contractor for recycling. Further, the recycled material that is sent to the part manufacturer (stage (3)) is suitable for closed loop material recycling process and the recycled material that is sent to the user of recycled material (stage (15)) is suitable for open loop material recycling process which is mentioned later.
Stage (15) is a stage of using recycled material. The recycled material in stage (14) is sent to a user of recycled material. Stage (16) is a stage of transformation into a raw material in which metal raw material is removed from printed circuit boards and shredding dust. Stage (17) is a stage of transformation into a raw material in which transformation is carried out by removing oil from the shredding dust, heating and chemical decomposition. Stage (18) is a stage of using the recycled raw material in which the raw materials recycled in previous stages (16) and (17) is sent to a recycling contractor for use. Stage (19) is a stage of recovering heat energy. A heat energy recovery contractor recovers heat energy by burning the shredding dust. Stage (20) is a stage of final waste. In general, a contractor in a final stage uses the waste for reclamation by filling in the ground.
This recycling system is mainly used for recycling office automation equipment such as image forming apparatus. This recycling system can also be applied to home electric appliances, cars etc.
However, the recycling system disclosed so far does not give any financial profit to the companies. On the contrary, the recycling puts excess financial burden on companies. Therefore, it was disadvantageous for companies to continue the recycling for a long period, and therefore, it was difficult to contribute to the conservation of environment.
For example, Japanese Patent Application Laid Open Publication No. 2001-30363 disclosed to mix a waste toner with a sintering material and sinter the mixture. In this case, the iron powder in the toner can be used as an iron source, a part of resins is burned and can be used as a substitute of coke breeze. This type of invention can achieve both objects viz. disposal of waste toner and use of iron powder and resin content. However, some toners include iron powder and some do not. Even in the toners that include an iron powder, the iron powder content is as low as about 50%. Therefore, the added value in financial terms of iron content in toner for iron manufacturer is low.
Apart from that, only a small part of the resin content in a toner can be used as a substitute of coke breeze and a majority of part of the resin content is transformed into gas and disposed as waste gas in waste gas disposal (treatment) equipment in the process of steel manufacturing. Furthermore, the resin content of a toner differs according to the type of a toner. Therefore, the sintering process devised to accommodate the variation in the type of toner affects the reduction of sintered steel. In order to minimize this effect on the reduction of sintered steel, the proportion of waste toner in the sintering process is controlled to 0.5%.
Thus, from the point of view of the toner processors, the use of waste toner does not added much value in financial terms. Hence, the providers of the toner, like the toner manufacturers, pay the toner disposers to get the toner disposed. The toner providers have to bear the recycling cost. For this reason, toner providers are not motivated to take positive attitude toward recycling the toner continuously.
However, in the field of metal refining like steel making or aluminum refining, the generation of the powder particles can not be avoided during the refining and dissolution processes that are carried out for achieving metal from ore. The powder particles include aluminum dross, aluminum ash, and aluminum dregs. Various proposals are made for recycling of these powder particles.
Using powder particles in a raw material of flux used in steel manufacturing (hereinafter, “flux”) is a technique of recycling the powder particles. The flux is an additive used for the purpose of improving the fluidity of the slag and reduction of iron oxide that exists in the slag of an electric furnace and a blast furnace. The flux is formed in a particular size, taking into consideration the handling and the working environment. Formation of a particular size using powder particles is called granulation.
It is known to mix a binder during the granulation to improve granularity, automorphic characteristics, and crushing strength. Japanese Patent Application Laid Open Publication No. 1992-200332 and Japanese Patent Publication (KOUKOKU) No. 1992-35621 disclose binders like polybasic acids such as dimeric acid and trimeric acid, pitch, tar, starch, carboxyl methyl cellulose, polyvinyl alcohol, and inorganic element based binders like cement and bentonite.
However, there is a need to add water when inorganic element based materials, polyvinyl alcohol, and carboxyl methylcellulose are used as binders. Starch has high absorbency and poor water resisting property due to which it reacts with water in aluminum dregs and generates hydrogen and ammonia gases. When a flux that has tar or pitch as a binder in it, is put into a blast furnace, a large quantity of black smoke is generated thereby worsening the working environment. Use of dimeric acid and trimeric acid as a binder in the flux results in affecting the automorphic characteristics of granulation, low recovery of flakes after granulation, and high proportion with respect to the powder particles thereby lowering the metal refining density. Moreover, use in the aluminum dregs starts a chemical reaction from the time of granulation thereby oxidizing aluminum. Therefore, the flux loses the product value by losing the reduction capacity.
Japanese Patent No. 2732898 also proposes phenol based resins and polyurethane based resins as resin binders. However, the phenol-based resins have poor formation characteristics and polyurethane resins are expensive which increase the cost of the flux.
Thus, in the present situation there is no recycling method available for recycling toner with positive attitude on long-term basis (continuously). There is no suitable binder available for flux manufacturers, which can suits the flux.